steel shielding calculations
Magnetic steel shielding may be required depending on the type of magnet, its Tesla field strength and the location on site.
The aim is to contain the spread of the strong magnetic field produced by an MRI magnet by installing magnetic steel shielding to protect sensitive medical equipment and minimise the risk to people with pacemakers and implants. If the proposed location of the magnet allows the 5 Gauss line to spread outside of the room this can have serious repercussions to members of the public in this area.
Another factor to take into consideration is interference from the outside world. Moving objects with high levels of ferrous magnetic metals such as vehicles and lift shafts can cause interference to the operation of the MR scanner. Introducing materials like magnetic steel shielding will contain the magnetic field and avoid interference from the outside world.
Envirotect can arrange magnetic steel shielding calculations and issue a detailed report providing modelling data and calculations for 5 Gauss containment.
The magnetic fields are modelled using finite element analysis (FEA) software package to recreate the magnet isolines to simulate the magnet. Shielding material is added to the model to reflect the dimensions of the controlled area and the resultant isolines, particularly the 5 Gauss isoline, are investigated to determine the performance of the containment.
The process is repeated on multiple iterations to determine the containment strategy which provides containment of the 5 Gauss isoline using the least amount of shielding material. The report details the key parameters of the 5 Gauss containment calculations to include the material type, thickness and placement relative to the magnet.
Confirmation of the Gauss containment design, which is included in the report, must be obtained from the magnet manufacturer to ensure that the intended shield design and any recommendations will not impact negatively on the MRI performance.
In order to produce the report and calculations envirotect require documentation detailing the magnetic source, susceptible equipment within the facility and CAD drawings detailing the layout of the facility including floor plans and section views.
Envirotect has a wealth of experience in calculating, designing, manufacturing and installing magnetic steel shielding, so feel free to contact us for more information.